The present invention is directed to a control system for use in a recreational vehicle, which system provides efficient automatic control of at least one major, electrically powered appliance, such as an air conditioner or a heater.
Recreational vehicles such as motor homes and the like are characterized by a unique set of appliance control problems. When such recreational vehicles are connected to a remote source of electrical power, severe constraints are typically placed on the current that can be drawn from the remote source. As used herein, the term "shore power" will be used to designate such a remote source of electrical power for a recreational vehicle, whether land or sea based.
This current constraint can have dramatic results. for example, if a recreational vehicle is connected to a 20 amp source of electrical power, and the recreational vehicle includes a 15 amp air conditioner, the simultaneous use of a microwave oven or a hair dryer with the air conditioner may well exceed the available current capacity of the remote source, thereby causing circuit breakers to trip or fuses to blow. The replacing of blown fuses or the resetting of tripped circuit breakers can represent a considerable inconvenience to a user of a recreational vehicle in such circumstances.
Another related problem is related to the fact that a variety of recreational vehicles include two air conditioning units or two heating units. When the recreational vehicle is relying on shore power, it is generally not feasible to run both air conditioners or both heaters simultaneously because of the power limitations of the shore power connection. For this reason, it has been customary to operate a single one of the two air conditioners from shore power and to leave the other off. This approach can represent a severe inconvenience in a situation where one air conditioner cools a first portion of the recreational vehicle, and the other air conditioner cools a second portion of the recreational vehicle. If only one conditioner is allowed to run, some portion of the recreational vehicle may not be cooled adequately. Furthermore, the approach of manually activating both of the air conditioners or heaters in alternating sequence requires considerable attention by the user.